Data synchronization method, apparatus, and system

Embodiments of the disclosure provide a data synchronization method, apparatus and system. The data synchronization method includes: receiving first modification data in primary storage; adding the first modification data to an asynchronous message queue; and sending the first modification data in the asynchronous message queue to standby storage. Embodiments of the present disclosure add modification data in primary storage to an asynchronous message queue, and send the modification data in the asynchronous message queue to standby storage by enabling one or more message sending threads, so that data synchronization between the primary storage and the standby storage is no longer restricted by the resources of the primary storage. The method reduces the time delay between the primary storage and the standby storage during data synchronization by sending data via multiple threads.